# How often does Earth cross the galaxy regions with higher supernovae activity?

According to Summa Technologiae, a book by a Polish author Stanisław Lem that based his science fiction novels on scientific research of the era, the Earth crossed in the moment of forming of life the arms of the Galaxy, with high supernovae activity, which triggered life creation. Afterwards, it moved to regions with low supernovae activity, which enabled the preservation of existing life.

I'd like to test the validity of this claim against current research. How often does the Earth cross regions with higher concentrations of stars (and therefore, much greater chance of gamma burst wipe)? Additionally, how many times the probability of nearby supernova explosion is higher in that regions?

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Have you read the relevant Wiki article? It has some information on this that cites some reliable sources, though I have no idea how accurate their citation of the material is. If you've already read this and are satisfied with it, what additional information are you looking for beyond this? –  called2voyage Oct 8 '13 at 20:44
@called2voyage I'm more interested in Earth movement through galaxy and changing density of supernovae candidates connected with it –  Lukasz Oct 8 '13 at 20:52

The paper "Frequency of nearby supernovae and climatic and biological catastrophes" by Clark, McCrea, and Stephenson published in Nature estimates (at 50% probability) that the Solar System passes within 10 parsecs of a supernova every 100 million years. This supernova would be part of a 20-parsec strip in which an estimated 50 supernovae occur.

They do speculate that a connection between the Solar System passing through these regions and climatic and biological events (such as ice ages) is possible.

You can read the paper yourself for more details. It's only two pages and you can purchase 48 hour access for \$5 from Readcube.

Source:

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Do this paper deals with varying probability of meeting supernova depending on in which region of galaxy is the Solar System in given moment of its history? –  Lukasz Jan 14 at 17:53
@ŁukaszL. In brief, yes. It does not get into a lot of detail and there is no solid density/time information. You might, however, find their discussion of how they got to their estimate interesting. –  called2voyage Jan 14 at 17:54
Basically they figure Type II supernovae are usually localized to the arms of the Milky Way. –  called2voyage Jan 14 at 17:55
OK, but do they provide any calculations or estimations, how much more probable is to meet nearby supernova there? –  Lukasz Jan 14 at 18:04
I've given you all the end results: 50% probability of passing within 10 parsecs of one supernova every 100 million years, a supernova which is in a group of 50 supernovas in a 20-parsec region. The rest of the detail in in their methods, not their results. –  called2voyage Jan 14 at 18:05
As for the supernova activity, humankind hasn't seen a supernova (excluding some theories), but our best bet to witness on would be Betelgeuse, it is already old for its size class and is expected to explode relatively soon (it may explode tomorrow or after a million years nobody knows exactly when) compared to its age.